Referring to FIGS. 1 and 2, a semiconductor package according to the prior art includes an integrated circuit (IC) semiconductor device 10, a plurality of leads 12 arranged around device 10, a plurality of wirebonds 14 each electrically coupling a respective lead 12 to a respective electrode of device 10, a die pad 16 supporting device 10, and molded housing 18 (depicted using slanted lines in FIGS. 1 and 3) molded over device 10, wirebonds 14, and at least portions of leads 12, and die pad 16.
Referring now to FIGS. 3 and 4, a package according to another prior art concept includes all of the elements of the package illustrated by FIGS. 1 and 2, except that device 10 is connected to leads 12 through solder bumps 20. The solder bumps serve to reduce the resistance of the package compared to wirebonding. Moreover, as is readily seen, solder bumps allow the device 10 to be supported on leads 12, obviating the need to provide a die pad 16.
To realize a package as depicted by FIGS. 3 and 4, device 10 must “bumped” with solder bumps or other bumps prior to disposition on leads 12. The bumping process is expensive and complex.
It is desirable to avoid the bumping process or pre-soldering process and yet take advantage of flip-mounting of a device onto leads.